Recording and reproducing apparatus of thin optical disc

Abstract

In an apparatus for recording and reproducing a thin optical disc by using the same optical system as that of a CD, a DVD or the like, the invention provides a technique which can stably rotate the thin optical disc at a high speed. The structure can be made such that a turbulence of an airflow is not generated even if the thin optical disc on a turn table is rotated at a high speed, by employing a transparent turn table and arranging a recording and reproducing head or the like in an opposite side to a thin optical disc mounting surface of the turn table.

1. A recording and reproducing apparatus comprising:
 a transparent turn table holding a thin optical disc; and 
 an optical system including a recording and reproducing head for recording and reproducing the thin optical disc, 
 wherein said optical system is arranged in an opposite side of said transparent turn table to a surface in which the thin optical disc is arranged, and a recording and reproducing light output by said optical system transmits through said transparent turn table and is focused on a recording surface of the thin optical disc, 
 wherein said optical system is constituted by a DVD optical system, 
 wherein a thickness of said transparent turn table and a protective film of said thin optical disc is adjusted in such a manner that an optical path length transmitting through said transparent turn table and the protective film of said thin optical disc becomes approximately equal to an optical path length of a substrate of a DVD disc in the DVD optical system. 
 
     
     
       2. A recording and reproducing apparatus as claimed in  claim 1 , wherein a spacer is arranged between said transparent turn table and the thin optical disc. 
     
     
       3. A recording and reproducing apparatus as claimed in  claim 2 , wherein an air layer is secured between said turn table and said thin optical disc, on the basis of said spacer. 
     
     
       4. A recording and reproducing apparatus as claimed in  claim 1 , further comprising a magnetic or mechanical means for fixing said thin optical disc on said transparent turn table. 
     
     
       5. A recording and reproducing apparatus as claimed in  claim 2 , further comprising a magnetic or mechanical means for fixing said thin optical disc on said transparent turn table. 
     
     
       6. A recording and reproducing apparatus as claimed in  claim 3 , further comprising a magnetic or mechanical means for fixing said thin optical disc on said transparent turn table.